Abiotic stresses such as nutritional imbalance, salt, light intensity, and high and low temperatures negatively affect plant growth and development. Through the course of evolution, plants developed multiple mechanisms to cope with environmental variations, such as physiological, morphological, and molecular adaptations. Epigenetic regulation, transcription factor activity, and post-transcriptional regulation operated by RNA molecules are mechanisms associated with gene expression regulation under stress. Epigenetic regulation, including histone and DNA covalent modifications, triggers chromatin remodeling and changes the accessibility of transcription machinery leading to alterations in gene activity and plant homeostasis responses. Soybean is a legume widely produced and whose productivity is deeply affected by abiotic stresses. Many studies explored how soybean faces stress to identify key elements and improve productivity through breeding and genetic engineering. This review summarizes recent progress in soybean gene expression regulation through epigenetic modifications and circRNAs pathways, and points out the knowledge gaps that are important to study by the scientific community. It focuses on epigenetic factors participating in soybean abiotic stress responses, and chromatin modifications in response to stressful environments and draws attention to the regulatory potential of circular RNA in post-transcriptional processing.

In recent years, significant efforts have been made to understand the phyllosphere microbiome. To clarify current research trends and identify knowledge gaps, we conducted a systematic review of the literature and investigated the methodologies used to analyze microbiome communities associated with plants, along with the objectives of these studies. Applying systematic review principles, we assessed 333 reports from the Web of Science database for eligibility. Articles were included if they presented original research on microbiomes associated with phyllosphere tissues identified by next-generation sequencing. Of these, 268 reports, published from 2009 to March 2025, were retrieved. These reports were used to extract data in a controlled and methodical manner. The analyses identified the most frequently studied plant species and primary tissues, the geographical locations sampled, the variables investigated in the phyllosphere microbiome, and the methodologies and tools employed. A comparison of the number of studies on below-ground (n=1562) versus above-ground tissue (n=375) underscores the relatively unexplored nature of above-ground research. We notice a surprisingly low number of studies from the Southern Hemisphere. Additionally, through data mining, we identify the most dominant bacteria and fungi reported in phyllosphere studies. Based on these findings, we offer recommendations for future research on the phyllosphere.

The phyllosphere microbiome contributes to plant health and adaptation, yet bacterial communities associated with Eugenia uniflora remain poorly characterized. This study investigated how developmental stage shapes the E. uniflora phyllosphere microbiome and assessed bacterial taxa and associations shared with other Myrtaceae species. The V3–V4 region of the 16S rRNA gene was sequenced from 19 E. uniflora samples representing young and mature trees, as well as 13 samples from mature trees representing three additional Myrtaceae genera (Myrcianthes, Plinia, and Psidium) and other Eugenia species. Community diversity, predicted functional potential, co-occurrence networks, and core taxa were analyzed. In E. uniflora, 1428 bacterial ASVs belonging to 17 phyla and 135 genera were identified, and bacterial community composition differed significantly between developmental stages. Young and mature trees showed distinct taxonomic profiles and predicted functional patterns. Network analysis revealed more connected bacterial communities in young plants and simpler networks in mature plants. Comparison with other Myrtaceae identified 17 core genera, including Methylobacterium–Methylorubrum, Hymenobacter, Sphingomonas, Bdellovibrio, and Terriglobus, which occurred in all 21 mature trees. Overall, developmental stage was associated with changes in the taxonomic, predicted functional potential, and network organization of the E. uniflora phyllosphere microbiome, while shared bacterial taxa and associations across the sampled Myrtaceae genera suggest conserved features of phyllosphere community assembly.